Упрощаем кастомизацию многоуровнего меню

<?php if (!defined('B_PROLOG_INCLUDED') || B_PROLOG_INCLUDED!==true)die();?>
<?if (!empty($arResult)):?>
   <?foreach($arResult as $i => $arItem):?>
      <a href="<?=$arItem['LINK']?>"><?=$arItem['TEXT']?></a>
   <?endforeach?>
<?endif;?>

if (!empty($arResult)) {
   $parentID = false;
   $subParentID = false;
   foreach($arResult as $i => $arItem) {
      if ($arItem['DEPTH_LEVEL'] == 1) {
         $parentID = $i;
         $arResult[$i]['ITEMS'] = array();
      } elseif ($arItem['DEPTH_LEVEL']==2 && $parentID!==false) {
         $arResult[$parentID]['ITEMS'][$i] = $arItem;
         $subParentID = $i;
         unset($arResult[$i]);
      } elseif ($arItem['DEPTH_LEVEL']==3 && isset($arResult[$parentID]['ITEMS'][$subParentID])) {
         if (!isset($arResult[$parentID]['ITEMS'][$subParentID]['ITEMS'])) {
            $arResult[$parentID]['ITEMS'][$subParentID]['ITEMS'] = array();
         }
         $arResult[$parentID]['ITEMS'][$subParentID]['ITEMS'][] = $arItem;
         unset($arResult[$i]);
      }
   }
   $arResult = array_values($arResult);
}